Short-time Tests Research Articles

Development of a Fluorescent Immunochromatographic Assay Based on Quantum Dot-Functionalized Two-Dimensional Monolayer Ti3C2 MXene Nanoprobes for the Simultaneous Detection of Influenza A Virus and SARS-CoV-2.

Accurate and rapid detection of the influenza A virus (FluA) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can effectively control their spread. We developed a colorimetric and fluorescent dual-functional two-channel immunochromatographic assay (ICA) biosensor to simultaneously detect the above-mentioned viruses. A unique two-dimensional Ti3C2-QD immunoprobe was established by adsorbing dense quantum dots (QDs) onto the light green monostromatic Ti3C2 MXene surface, resulting in light green colorimetric and superior fluorescence signals and guaranteeing high sensitivity, stability, and excellent liquidity for ICA detection. Rapid visual screening for FluA and SARS-CoV-2 infections was applicable via a green colorimetric signal. Sensitive and quantitative detection of viruses in their early stages of infection was performed by using the fluorescence signal. Our proposed Ti3C2-QD-ICA biosensor can simultaneously detect 1 ng/mL or 2.4 pg/mL FluA and 1 ng/mL or 6.2 pg/mL SARS-CoV-2 via its colorimetric or fluorescence signals, respectively, with a short testing time (20 min), good reproducibility, specificity, and accuracy. In addition, this method demonstrated sensitivity higher than that of the conventional AuNP-based ICA method in throat swab samples. Hence, our proposed Ti3C2-QD-ICA method can be potentially applied for the rapid, ultrasensitive, and multiplex detection of respiratory viruses.

Nondestructive Evaluation of Residual Stress in Shot Peened Inconel Using Ultrasonic Minimum Reflection Measurement.

Shot peening is a process wherein the surface of a material is impacted by small, spherical metal shots at high velocity to create residual stresses. Nickel-based superalloy is a material with high strength and hardness along with excellent corrosion and fatigue resistance, and it is therefore used in nuclear power plants and aerospace applications. The application of shot peening to INCONEL, a nickel-based superalloy, has been actively researched, and the measurement of residual stresses has been studied as well. Previous studies have used methods such as perforation strain gauge analysis and X-ray diffraction (XRD) to measure residual stress, which can be evaluated with high accuracy, but doing so damages the specimen and involves critical risks to operator safety due to radiation. On the other hand, ultrasonic testing (UT), which utilizes ultrasonic wave, has the advantage of relatively low unit cost and short test time. One UT method, minimum reflection measurement, uses Rayleigh waves to evaluate the properties of material surfaces. Therefore, the present study utilized ultrasonic minimum reflectivity measurements to evaluate the residual stresses in INCONEL specimens. Specifically, this study utilized ultrasonic minimum reflection measurements to evaluate the residual stress in INCONEL 718 specimens. Moreover, an estimation equation was assumed using exponential functions to estimate the residual stress with depth using the obtained data, and an optimization problem was solved to determine it. Finally, to evaluate the estimated residual stress graph, the residual stress of the specimen was measured and compared using the XRD method.

Classification of multiple power quality disturbances based on continuous wavelet transform and lightweight convolutional neural network

AbstractAiming at the problems of noise interference and too many network parameters for power quality disturbances' (PQDs') classification based on deep learning, the lightweight convolutional neural network combining maximum likelihood Kalman filter and continuous wavelet transform is proposed. In this proposed method, the disturbed PQD signals are denoised by maximum likelihood Kalman filter, and then the denoised PQDs are converted to time‐frequency diagrams, which can provide rich time and frequency domain information, and finally the lightweight convolution neural network is used for automatically extracting and classifying multiple PQDs. To verify the effectiveness and superiority of the proposed method, a variety of PQDs were tested under different noise levels, the experiment results indicate that the average classification accuracy can reach more than 99% even in the case of 10 dB noise. Compared with the existing classification methods, the accuracy and noise immunity ability are improved. Additionally, the proposed method has decided advantages, as evidenced by its low parameter count of 0.73M and short average test time with only 0.7 ms.

SARS-CoV-2 detection with type I-A CRISPR “FALCON” system

CRISPR-Cas systems are currently applied in the detection of infectious diseases as a rapid and accurate alternative for the traditional RT-PCR (reverse-transcription polymerase chain reaction) test. The type I-A CRISPR-Cas nucleic acid detection system has been proven to achieve efficient detection through a 15-minute one-pot reaction at 85°C. For this project, a type I-A system “FALCON” (Fast Agent in Limited COVID Nucleic acid detection) was created to detect SARS-CoV-2 and its variants. The system’s guide RNA is designed with the N gene of SARS-CoV-2. When tested with samples containing SARS-CoV-2 pseudovirus, the system’s embedded Cas3 enzyme is activated upon guide RNA recognition and collaterally cleaves FQ (fluorophore-quencher) reporters, producing a fluorescent sample where the amount of fluorescence is proportional to the viral load. In addition, FALCON’s results are highly consistent with those of RT-PCR but requires much less instrumentation and shorter testing time, and can differentiate among virus variants. FALCON can be developed into commercial SARS-CoV-2 self-testing kits, or used in detection and differentiation of other diseases with a modified guide RNA.

An Interleaving Guided Metamorphic Testing Approach for Concurrent Programs

Concurrent programs are normally composed of multiple concurrent threads sharing memory space. These threads are often interleaved, which may lead to some non-determinism in execution results, even for the same program input. This poses huge challenges to the testing of concurrent programs, especially on the test result verification, that is, the prevalent existence of the oracle problem. In this paper, we investigate the application of metamorphic testing, a mainstream technique to address the oracle problem, into the testing of concurrent programs. Based on the unique features of interleaved executions in concurrent programming, we propose an extended notion of metamorphic relations, the core part of metamorphic testing, which are particularly designed for the testing of concurrent programs. A comprehensive testing approach, namely ConMT, is thus developed and a tool is built to automate its implementation on concurrent programs written in Java. Empirical studies have been conducted to evaluate the performance of ConMT, and the experimental results show that in addition to addressing the oracle problem, ConMT outperforms the baseline traditional testing techniques with respect to higher degree of automation, better bug-detection capability, and shorter testing time. It is clear that ConMT can significantly improve the cost-effectiveness for the testing of concurrent programs and thus advances the state of the art in the field. The study also brings novelty into metamorphic testing, hence promoting the fundamental research of software testing.

Investigation and Improvement of Test Methods for Capacitance and DCESR of EDLC Cells.

The quick and accurate characterization of commercial electrochemical double-layer capacitor (EDLC) cells, especially their capacitance and direct-current equivalent series internal resistance (DCESR), is of great significance for the design, maintenance, and monitoring of EDLCs used in areas of energy, sensors, electric power, construction machinery, rail transit, automobile transportation, and military. In this study, the capacitance and DCESR of three commercial EDLC cells with similar performance were determined and compared by following the three commonly-used standards of IEC 62391, Maxwell, and QC/T741-2014, which are significantly different in test procedures and calculation methods. The analysis of the test procedures and results demonstrated that the IEC 62391 standard has the disadvantages of a large testing current, long testing time, and a complex and inaccurate DCESR calculation, whereas the Maxwell standard has the disadvantages of a large testing current, a small capacitance, and large DCESR testing results, and furthermore the QC/T 741 standard has the disadvantages of a high resolution requirement for the equipment and small DCESR results. Therefore, an improved method was proposed to determine the capacitance and DCESR of EDLC cells by short-time constant voltage charging and discharging interruption methods, respectively, with the advantages of high accuracy, low equipment requirements, short testing time, and the easy calculation of DCESR over the original three standards.

Application of a Novel One-Side Cell Quartz Crystal Microbalance Immunosensor in the Determination of Alpha-Fetoprotein from Human Serum.

The rapid and accurate detection of alpha-fetoprotein (AFP) levels is of great significance for the diagnosis and later treatment evaluation of liver cancer. In this study, a novel integrated quartz crystal microbalance (QCM) immunosensor based on the design to contact liquids on one side only was developed for the label-free detection of AFP. Anti-AFP mouse monoclonal antibodies were immobilized onto the upper electrode surface of the pre-treatment crystals using the staphylococcus aureus protein A. The AFP antigens in human serum were captured by specific surface-coated antibodies, and testing was carried out by monitoring the corresponding changes in frequency. The concentration range of the antigen detected was 13-760 ng/mL. The frequency characteristics of the process of antibody immobilization were investigated in detail, and high reproducibility of AFP antibody immobilization was achieved (standard deviation (SD) = 2.2 Hz). The developed QCM measurement system demonstrated a short test time (only 30 min), good reproducibility (the biological activity can still maintain more than 90% of the first test till it is reused five times), and accuracy as good as the one achieved with the radioimmunoassay (the maximum relative deviation = 4.8%). The designed QCM test system can easily and quickly detect AFP concentrations up to 760 ng/mL, indicating that the developed QCM assay is likely to lead to an alternative approach in large-scale screening for liver cancer in the near future.

Germination and Early Seedling Growth of Three Arabica Coffee Varieties at Four Seed Soaking Water Temperatures

It takes three weeks to analyze the germination percentage of Arabica coffee seeds germinated using paper and a three-day water-soaking method. This 3- week period is considered too long for seed distribution to remote areas. Thus, we need to modify this germination test needs to be modified to have a shorter test time. Temperature treatment is one method to break the seed dormancy period for faster germination. This study aimed to obtain a faster and more precise method of germination test on Arabica coffee seeds. This study employed a 3 x 4 factorial complete randomized block design with three replications in which Arabica coffee varieties of Gayo-1, Kartika-1, and Sigararutang as the first factor and the temperature of the soaking water of the seeds (25 0C, 50 0C, 75 0C, and 90 0C) as the second factor. The research was conducted at the Plant Breeding Laboratory, Indonesian Coffee and Cocoa Research Institute (ICCRI), for four months. Findings showed that the interaction between treatments was only found in seed germination percentage. Soaking in room temperature water (control) for three days was better than using water at 50 0C, 75 0C, and 90 0C on the germination percentage, sprout length, and vigor index. Observations of Arabica seed germination could be shortened to 14 days compared to the standard 21-day observation. During the seedling phase, the shoot growth and root growth of the Arabica coffee seeds soaked in water at 50 0C showed no significant difference from the control. Soaking at 75 0C and 90 0C damaged the embryo and resulted in rotten seeds. Different varieties led to different germination percentages, sprout lengths, and fresh weight of seedling shoots. The method of soaking at 50 0C for 30 minutes could be used as an alternative in germination test of Arabica coffee seeds because it showed small negative effect on germinated seed and seedling quality but it shorten thetesting time for three days.

Rapid microfluidic-thromboelastography (μ-TEG) for evaluating whole blood coagulation and fibrinolysis at elevated shear rates

The assessment of hemostasis and fibrinolysis is essential in emergency settings to make timely medical decisions. While conventional thromboelastography (TEG) analyzers provide comprehensive information on blood clotting, their long test times are often unsuitable for emergency patients. In this study, we propose an innovative method of microfluidic thromboelastography (μ-TEG) that rapidly measures the viscoelastic properties of blood coagulation in oscillating flow through circular tubes. Our μ-TEG system moves a blood sample back and forth through a circular tube subjected to sinusoidal pressure, generating shear rates ranging from 1.2 to 20 s−1, higher than those of conventional TEGs. The movements are monitored by a pressure sensor and converted to a conventional TEG. Key parameters such as MA and Ly30 can be acquired within 10–12 min for normal samples. Our study showed that the increased shear rate in the μ-TEG system alters the coagulation mechanism, resulting in increased coagulation strength and rapid fibrinolysis. Despite the short test time, the μ-TEG showed good agreement with the TEG5000. The rapid measurement of μ-TEG makes it a useful tool for analyzing hemostasis and fibrinolysis in emergency and operating rooms.

A Combination of Laboratory Testing, RCE, and Corrosion Loop for Inhibitor Selection

Corrosion inhibitors are evaluated in the oil industry with electrochemical tests of resistance to linear polarization with rotating cylinders following ASTM G170 and NACE 3T199 standards. With these tests, we can determine the corrosion rate (CR) and efficiency of corrosion inhibitors. In this work, a corrosion test protocol used by hydrocarbon-producing companies for the testing of corrosion inhibitors was used. This protocol consists of a 1045 carbon steel working electrode in a NACE solution composed of 9.62% NaCl, 0.45% CaCl2, 0.19% MgCl2, and 89.74% H2O, at a temperature of 65 °C and saturated with CO2. Each inhibitor tested was subjected to a series of 6000-4000-2000-4000-6000 rpm tests using rotating cylinder electrodes (RCEs). These electrochemical studies were carried out with the rotating cylinder to evaluate the ability of the inhibitor to prevent the corrosion of carbon steel in the presence of a centrifugal force. In our opinion, this test does not provide corrosion engineers with enough information to be used as a predictive tool, since what is obtained is the CR in a very short testing time. This document proposes the use of two more appropriate test methodologies, the rotating cylinder electrode (RCE) and the flow loop (FL), to evaluate the performance of the corrosion inhibitor. For the FL, the selected flow rate was 1.2 m/s, the same rate that fluids have in oil company pipelines installed in Neuquén, Argentina. Firstly, according to the company’s protocol, inhibitors are required to have an efficiency greater than or equal to 90% in RCE tests; therefore, inhibitors that meet these requirements were tested in the FL test. Unlike the RCE test, the FL test represents the experimental conditions of the laboratory that are closest to reality, for the evaluation of the performance of the inhibitors used in the pipelines of the oil and gas industry. FL tests have several problems involving corrosion, erosion, abrasion, biphasic fluids, the time it takes for the inhibitor to become effective, and the duration of its effectiveness.

Quantitative Identification of ADHD Tendency in Children With Immersive Fingertip Force Control Tasks.

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder that affects children. However, the traditional scale-based diagnosis methods rely more on subjective experiences, leading to a demand of objective biomarkers and quantified diagnostic methods. This study proposes a quantitative approach for identifying ADHD tendency based on fingertip pressing force control paradigm with immersive visual feedback. By extracting nine behavioral features from reaction time and dynamic force fluctuation features with high temporal and amplitude resolution, the proposed method can effectively capture the continuous changes in attention levels for ADHD diagnosis. The extracted features were analyzed using independent sample t-test and Pearson correlation to determine their association with ADHD-RS scale scores. Results showed that 12 statistical indicators were effective for distinguishing ADHD children from typically developed children, and several features of force control ability were also associated with core ADHD symptoms. A support vector machine (SVM) based classifier is trained for ADHD diagnosis and achieved an accuracy of 78.5%. This work provides an objective and quantitative approach for identifying ADHD tendency within a short testing time, and reveals the inherent correlation between the attention levels and the extracted features of reaction time and force fluctuation dynamics.

Design and calibration test of a support force measuring system for hypersonic vehicle aerodynamic measurement

With the development of air-breathing integrated vehicle test models equipped with engines, the designing of traditional internal balance force measuring systems has become complicated. This is partly because hypersonic vehicle models have slender bodies, and engine systems inside such model cavities are densely distributed, thereby limiting the space available to house traditional internal balance systems. Moreover, traditional force measuring systems are assembled mechanical systems, and their dynamic force transmission characteristics are inevitably degraded under extremely short test time conditions. Thus, herein, we propose a support force measuring system that integrates the traditional internal balance system with a support in an integral design. The designed internal triangular concurrent force system considerably reduces the additional moment generated by the thrust/resistance force. Calibration tests reveal that the new system demonstrates good linearity and repeatability, and the results prove the correctness of the triangular concurrent force system structure principle.

Ultrasensitive Fluorescence Lateral Flow Assay for Simultaneous Detection of Pseudomonas aeruginosa and Salmonella typhimurium via Wheat Germ Agglutinin-Functionalized Magnetic Quantum Dot Nanoprobe.

Point-of-care testing methods for the rapid and sensitive screening of pathogenic bacteria are urgently needed because of the high number of outbreaks of microbial infections and foodborne diseases. In this study, we developed a highly sensitive and multiplex lateral flow assay (LFA) for the simultaneous detection of Pseudomonas aeruginosa and Salmonella typhimurium in complex samples by using wheat germ agglutinin (WGA)-modified magnetic quantum dots (Mag@QDs) as a universal detection nanoprobe. The Mag@QDs-WGA tag with a 200 nm Fe3O4 core and multiple QD-formed shell was introduced into the LFA biosensor for the universal capture of the two target bacteria and provided the dual amplification effect of fluorescence enhancement and magnetic enrichment for ultra-sensitivity detection. Meanwhile, two antibacterial antibodies were separately sprayed onto the two test lines of the LFA strip to ensure the specific identification of P. aeruginosa and S. typhimurium through one test. The proposed LFA exhibited excellent analytical performance, including high capture rate (>80%) to the target pathogens, low detection limit (<30 cells/mL), short testing time (<35 min), and good reproducibility (relative standard deviation < 10.4%). Given these merits, the Mag@QDs-WGA-based LFA has a great potential for the on-site and real-time diagnosis of bacterial samples.

Preparation and application of graphene oxide functionalized melamine-formaldehyde aerogel coated solid-phase microextraction tube

因具有良好的萃取性能,有机气凝胶已被应用于样品前处理领域,为了进一步改善其对多环芳烃类污染物的萃取能力,利用氧化石墨烯对三聚氰胺-甲醛气凝胶进行改性,制备了一种氧化石墨烯功能化三聚氰胺-甲醛气凝胶,将其作为萃取涂层涂覆到不锈钢丝表面,通过扫描电镜和X射线光电子能谱对萃取涂层进行表征,结果表明氧化石墨烯并未破坏气凝胶的三维网络多孔结构。将4根气凝胶涂覆的不锈钢丝装进一根长度30 cm、内径0.75 mm的聚醚醚酮管内,制备了一种新型的纤维填充型固相微萃取管。将萃取管与高效液相色谱联用,构建管内固相微萃取-液相色谱在线富集分析系统。以8种多环芳烃(萘(Nap)、苊烯(Acy)、苊(Ace)、芴(Flu)、菲(Phe)、蒽(Ant)、荧蒽(Fla)和芘(Pyr))作为模型分析物,评价了萃取管的萃取性能,考察了氧化石墨烯对气凝胶萃取性能的改善,结果表明萃取效率被提升至最高2.5倍。详细考察了样品体积、样品流速、样品中有机溶剂浓度以及脱附时间对于萃取效率的影响,并建立了管内固相微萃取-液相色谱在线分析方法。该法对8种多环芳烃分析物的检出限为0.001~0.005 μg/L,萘、苊烯、苊、芴的线性范围为0.017~20.0 μg/L,菲、蒽的线性范围为0.010~20.0 μg/L,荧蒽和芘的线性范围为0.003~15.0 μg/L,精密度良好(日内重复性RSD≤4.8%,日间重复性RSD≤8.6%)。研究所发展的分析方法比已报道的某些分析方法具有更好的灵敏度、更宽的线性范围和更短的分析时间,并具有在线富集和在线分析的独特优点。将该分析方法应用于常见饮用水(包括瓶装矿泉水和饮水机的直饮水)中多环芳烃的分析检测,加标回收率试验结果(76.3%~132.8%)表明该分析方法能够高灵敏、快速、准确地检测饮用水中痕量多环芳烃污染物。经过稳定性考察,发现研究所制备的固相微萃取管在实验过程中表现出良好的使用寿命和化学稳定性。

Experimental designs for accelerated degradation tests based on linear mixed effects models

Accelerated degradation testing has considerable significance in reliability inference due to its ability to provide accurate estimation of lifetime characteristics of highly reliable systems within a relatively short testing time period. The measured data from particular experiments at high stress conditions are extrapolated, through a technically reasonable statistical model, to obtain estimates of certain reliability properties under normal use levels. In this work, we consider repeated measures accelerated degradation tests with multiple stress variables, where the degradation path is assumed to follow a linear mixed effects model which is quite common in settings when repeated measures are made. As opposed to the vast majority of numerical derivations in the literature, we contribute in this work with analytical results in regards to optimal experimental designs for minimizing the asymptotic variance for estimating the median failure time under normal use conditions when the time points for measurements are fixed in advance.

Electroreduction of oxygen on iron- and cobalt-containing nitrogen-doped carbon catalysts prepared from the rapeseed press cake

• Nitrogen, Co- and/or Fe-doped nanocarbons prepared from rapeseed press cake. • ORR activity of Fe-containing catalysts is close to that of Pt/C in 0.1 M KOH. • Inhibition of ORR by CN − ions shows the existence of MN x centres. • Catalysts show high methanol tolerance and good stability. • In AEMFC , P max = 131 mW cm −2 achieved with bimetallic catalyst. Transition metal-containing nitrogen-doped carbon catalysts for the electrochemical oxygen reduction reaction (ORR) were prepared from inexpensive biomass - rapeseed press cake; cobalt and/or iron salts and dicyandiamide were employed as metal and nitrogen sources. After acid treatment, the catalysts showed excellent electrocatalytic ORR activity in rotating disk electrode experiments in 0.1 M KOH solution, comparable to that of Pt/C (20 wt%) catalyst; good tolerance to methanol and high stability in short-time tests. The bimetallic catalyst displayed moderate performance as cathode material in anion exchange membrane fuel cell (AEMFC) test, by reaching the peak power density of 131 mW cm −2 .

Analysis and Application of Data Mining Technology for College English Education Integration

With the development and application of information fusion technology, English education can realize intelligent application under multi-information fusion technology. In view of the low degree of educational informationization and single application of intelligent methods in the process of education, this paper puts forward the application of multi-technology in English education, so as to improve the education level and application skills. Firstly, this paper explains the educational application technology, especially the analysis of decision tree and linear regression method in data mining technology, and puts forward the framework and system structure diagram of English education system. In the experiment, the application of different methods is compared, and the results show that the decision number method has higher weight in weight analysis. According to the situation of different course quantity, 50%–80% of the course workload can be completed under multi-information fusion. However, in the amount of homework completion, most of the personnel can complete the homework, which has a good application effect. In different English majors, different research methods have different educational purposes and different teaching effects. Through the system interface and system performance testing, using the data mining method has better UI test results and shorter test time.

Comparison of different assays for the detection of anticyclic citrullinated peptide antibodies in patients with rheumatoid arthritis.

ObjectiveTo evaluate a novel fully automated immunoturbidimetric assay developed by Qiangsheng Biotechnology Company for the detection of anticyclic citrullinated peptide antibodies (anti-CCP) in serum of patients with rheumatoid arthritis (RA) and compare it to the conventional EUROIMMUN- anti-CCP ELISA. Two other commonly used automated assays, the Elecsys anti-CCP assay, an ECLIA that is run on the Modular Analystics E170 (Cobas Diagnostics, Germany), and an anti-CCP CLIA developed by YHLO that is run on the iFlash 3000 Chemiluminescence Immunoassay Analyzer, were included as reference standards.MethodsA total of 264 serum samples were collected from patients attending the First People’s Hospital of Wenling affiliated to Wenzhou Medical University between July 2020 and November 2020. These included 131 serum samples collected from patients with RA, 70 serum samples collected from patients with other autoimmune diseases, and 63 serum samples collected from healthy controls at a physical examination. The clinical performance and sensitivity and specificity of the four anti-CCP assays for the diagnosis of RA were compared using receiver operating characteristic (ROC) curve analysis.ResultsThe Kappa statistic indicated almost perfect agreement between the EUROIMMUN-anti-CCP ELISA and the Elecsys anti-CCP ECLIA (Cobas) (0.863), the EUROIMMUN-anti-CCP ELISA and the anti-CCP CLIA (YHLO) (0.862), and the Elecsys anti-CCP ECLIA (Cobas) and the anti-CCP CLIA (YHLO) (0.816). On ROC curve analysis, AUC values were 0.955 for the EUROIMMUN-anti-CCP ELISA, 0.948 for the anti-CCP CLIA (YHLO), 0.947 for the Elecsys anti-CCP ECLIA (Cobas) and 0.903 for Qiangsheng, indicating all the assays had a good diagnostic performance for RA.ConclusionThe anti-CCP assays provided similar diagnostic information. The novel fully automated immunoturbidimetric assay for anti-CCP developed by Qiangsheng Biotechnology Company may be especially useful for large scale clinical screening in RA as it has a shorter testing time than the commercially available alternatives.

Rapid detection of porcine circovirus type 4 via multienzyme isothermal rapid amplification.

Porcine circovirus type 4 (PCV4) is a newly emerging pathogen that was first detected in 2019 and is associated with diverse clinical signs, including respiratory and gastrointestinal distress, dermatitis and various systemic inflammations. It was necessary to develop a sensitive and specific diagnostic method to detect PCV4 in clinical samples, so in this study, a multienzyme isothermal rapid amplification (MIRA) assay was developed for the rapid detection of PCV4 and evaluated for sensitivity, specificity and applicability. It was used to detect the conserved Cap gene of PCV4, operated at 41°C and completed in 20 min. With the screening of MIRA primer-probe combination, it could detect as low as 101 copies of PCV4 DNA per reaction and was highly specific, with no cross-reaction with other pathogens. Further assessment with clinical samples showed that the developed MIRA assay had good correlation with real-time polymerase chain reaction assay for the detection of PCV4. The developed MIRA assay will be a valuable tool for the detection of the novel PCV4 in clinical samples due to its high sensitivity and specificity, simplicity of operation and short testing time.

Analytic investigation on error of heat flux measurement and data processing for large curvature models in hypersonic shock tunnels

Due to short test time, heat conduction was considered as transient in hypersonic shock tunnels. The heat flux measurement and data processing were operated basing on one-dimensional semi-infinite heat conduction theory. However, for models with local large curvature or small radius, it resulted in significant compression or expansion of space for heat transfer, or lateral heat conduction, which made the hypothesis of one-dimensional unsatisfied and errors. In this paper, approximate solutions for the unsteady heat conduction in cylindrically convex and concave shells were established, and were used for further analysis of the errors, with forms of heating load, location and curvature radius of heated surface taken into consideration.